1/*
2 * Copyright 2009-2012 Niels Provos and Nick Mathewson
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 * 3. The name of the author may not be used to endorse or promote products
13 *    derived from this software without specific prior written permission.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26#include "event2/event-config.h"
27
28/* With glibc we need to define this to get PTHREAD_MUTEX_RECURSIVE. */
29#define _GNU_SOURCE
30#include <pthread.h>
31
32struct event_base;
33#include "event2/thread.h"
34
35#include <stdlib.h>
36#include <string.h>
37#include "mm-internal.h"
38#include "evthread-internal.h"
39
40static pthread_mutexattr_t attr_recursive;
41
42static void *
43evthread_posix_lock_alloc(unsigned locktype)
44{
45	pthread_mutexattr_t *attr = NULL;
46	pthread_mutex_t *lock = mm_malloc(sizeof(pthread_mutex_t));
47	if (!lock)
48		return NULL;
49	if (locktype & EVTHREAD_LOCKTYPE_RECURSIVE)
50		attr = &attr_recursive;
51	if (pthread_mutex_init(lock, attr)) {
52		mm_free(lock);
53		return NULL;
54	}
55	return lock;
56}
57
58static void
59evthread_posix_lock_free(void *_lock, unsigned locktype)
60{
61	pthread_mutex_t *lock = _lock;
62	pthread_mutex_destroy(lock);
63	mm_free(lock);
64}
65
66static int
67evthread_posix_lock(unsigned mode, void *_lock)
68{
69	pthread_mutex_t *lock = _lock;
70	if (mode & EVTHREAD_TRY)
71		return pthread_mutex_trylock(lock);
72	else
73		return pthread_mutex_lock(lock);
74}
75
76static int
77evthread_posix_unlock(unsigned mode, void *_lock)
78{
79	pthread_mutex_t *lock = _lock;
80	return pthread_mutex_unlock(lock);
81}
82
83static unsigned long
84evthread_posix_get_id(void)
85{
86	union {
87		pthread_t thr;
88#if _EVENT_SIZEOF_PTHREAD_T > _EVENT_SIZEOF_LONG
89		ev_uint64_t id;
90#else
91		unsigned long id;
92#endif
93	} r;
94#if _EVENT_SIZEOF_PTHREAD_T < _EVENT_SIZEOF_LONG
95	memset(&r, 0, sizeof(r));
96#endif
97	r.thr = pthread_self();
98	return (unsigned long)r.id;
99}
100
101static void *
102evthread_posix_cond_alloc(unsigned condflags)
103{
104	pthread_cond_t *cond = mm_malloc(sizeof(pthread_cond_t));
105	if (!cond)
106		return NULL;
107	if (pthread_cond_init(cond, NULL)) {
108		mm_free(cond);
109		return NULL;
110	}
111	return cond;
112}
113
114static void
115evthread_posix_cond_free(void *_cond)
116{
117	pthread_cond_t *cond = _cond;
118	pthread_cond_destroy(cond);
119	mm_free(cond);
120}
121
122static int
123evthread_posix_cond_signal(void *_cond, int broadcast)
124{
125	pthread_cond_t *cond = _cond;
126	int r;
127	if (broadcast)
128		r = pthread_cond_broadcast(cond);
129	else
130		r = pthread_cond_signal(cond);
131	return r ? -1 : 0;
132}
133
134static int
135evthread_posix_cond_wait(void *_cond, void *_lock, const struct timeval *tv)
136{
137	int r;
138	pthread_cond_t *cond = _cond;
139	pthread_mutex_t *lock = _lock;
140
141	if (tv) {
142		struct timeval now, abstime;
143		struct timespec ts;
144		evutil_gettimeofday(&now, NULL);
145		evutil_timeradd(&now, tv, &abstime);
146		ts.tv_sec = abstime.tv_sec;
147		ts.tv_nsec = abstime.tv_usec*1000;
148		r = pthread_cond_timedwait(cond, lock, &ts);
149		if (r == ETIMEDOUT)
150			return 1;
151		else if (r)
152			return -1;
153		else
154			return 0;
155	} else {
156		r = pthread_cond_wait(cond, lock);
157		return r ? -1 : 0;
158	}
159}
160
161int
162evthread_use_pthreads(void)
163{
164	struct evthread_lock_callbacks cbs = {
165		EVTHREAD_LOCK_API_VERSION,
166		EVTHREAD_LOCKTYPE_RECURSIVE,
167		evthread_posix_lock_alloc,
168		evthread_posix_lock_free,
169		evthread_posix_lock,
170		evthread_posix_unlock
171	};
172	struct evthread_condition_callbacks cond_cbs = {
173		EVTHREAD_CONDITION_API_VERSION,
174		evthread_posix_cond_alloc,
175		evthread_posix_cond_free,
176		evthread_posix_cond_signal,
177		evthread_posix_cond_wait
178	};
179	/* Set ourselves up to get recursive locks. */
180	if (pthread_mutexattr_init(&attr_recursive))
181		return -1;
182	if (pthread_mutexattr_settype(&attr_recursive, PTHREAD_MUTEX_RECURSIVE))
183		return -1;
184
185	evthread_set_lock_callbacks(&cbs);
186	evthread_set_condition_callbacks(&cond_cbs);
187	evthread_set_id_callback(evthread_posix_get_id);
188	return 0;
189}
190